Largely unnoticed by the migration literature, business migration has established itself as a form of labour migration that is substantial in terms of numbers and receives preferential treatment in international and national migration law. Intra- corporate transferees, contractual service suppliers and business visitors all fall within this category and benefit from facilitated admission procedures agreed under trade agreements and corresponding provisions in national legislation. Assigned for temporary stays and retaining their work contract in the home country, these business migrants represent a “market model” of migration policy exploiting the economic benefits of human movement while avoiding migrants’ integration into the host countries’ labour market and society. This article conceptualizes business migration at the nexus of trade law, international labour markets and migration research and uses a mix of legal analysis, population register and other statistical data as well as survey data from Switzerland to demonstrate the scale and importance of this under-investigated yet significant type of economic migration. Amounting to nearly half of the regulated labour immigration into Switzerland, business migration is strongly associated with trade and investment ties as well as the presence of multinational companies. In contrast, trade agreements facilitating this type of labour mobility have no systematic effect.